[rfc patch 3/6] lib/index: Add another layer of indirection in filtering

[David Bremner]

We could add a second gmime filter subclass, but prefer to avoid
duplicating the boilerplate.
---
 lib/index.cc | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/lib/index.cc b/lib/index.cc
index 1c04cc3d..74a750b9 100644
--- a/lib/index.cc
+++ b/lib/index.cc
@@ -29,6 +29,8 @@
 typedef struct _NotmuchFilterDiscardUuencode NotmuchFilterDiscardUuencode;
 typedef struct _NotmuchFilterDiscardUuencodeClass NotmuchFilterDiscardUuencodeClass;
 
+typedef void (*filter_fun) (GMimeFilter *filter, char *in, size_t len, size_t prespace,
+			    char **out, size_t *outlen, size_t *outprespace);
 /**
  * NotmuchFilterDiscardUuencode:
  *
@@ -57,6 +59,7 @@ typedef struct _NotmuchFilterDiscardUuencodeClass NotmuchFilterDiscardUuencodeCl
 struct _NotmuchFilterDiscardUuencode {
     GMimeFilter parent_object;
     GMimeContentType *content_type;
+    filter_fun real_filter;
     int state;
 };
 
@@ -110,7 +113,14 @@ filter_copy (GMimeFilter *gmime_filter)
 
 static void
 filter_filter (GMimeFilter *gmime_filter, char *inbuf, size_t inlen, size_t prespace,
-	       char **outbuf, size_t *outlen, size_t *outprespace)
+	       char **outbuf, size_t *outlen, size_t *outprespace) {
+    NotmuchFilterDiscardUuencode *filter = (NotmuchFilterDiscardUuencode *) gmime_filter;
+    (*filter->real_filter)(gmime_filter, inbuf, inlen, prespace, outbuf, outlen, outprespace);
+}
+
+static void
+filter_filter_uuencode (GMimeFilter *gmime_filter, char *inbuf, size_t inlen, size_t prespace,
+			char **outbuf, size_t *outlen, size_t *outprespace)
 {
     NotmuchFilterDiscardUuencode *filter = (NotmuchFilterDiscardUuencode *) gmime_filter;
     register const char *inptr = inbuf;
@@ -223,7 +233,7 @@ notmuch_filter_discard_uuencode_new (GMimeContentType *content_type)
     filter = (NotmuchFilterDiscardUuencode *) g_object_newv (type, 0, NULL);
     filter->state = 0;
     filter->content_type = content_type;
-
+    filter->real_filter = filter_filter_uuencode;
     return (GMimeFilter *) filter;
 }
 
-- 
2.11.0